6.3 trace Default Format

If you use trace rather than
printf to capture data, the
dtrace command formats the results by using a
default output format. If the data is 1, 2, 4, or 8 bytes in size,
the result is formatted as a decimal integer value. If the data is
any other size, and is a sequence of printable characters if
interpreted as a sequence of bytes, it is printed as an ASCII
string. If the data is any other size, and is not a sequence of
printable characters, it is printed as a series of byte values
that is formatted as hexadecimal integers.